The present invention relates to an immobilized enzyme in which (S)-hydroxynitrile lyase is immobilized in an immobilization carrier with a high absorption ratio (or adsortion ratio), a method for producing said immobilized enzyme, and a method for producing optically active cyanohydrin using said immobilized enzyme.
(S)-hydroxynitrile lyase is useful as an enzyme for synthesizing optically active cyanohydrins. In organic solvent reaction systems which are ordinarily used enzymatic synthesizing of the compounds, the enzyme are used, for example, as immobilized enzymes for dispersing the enzyme in the reaction system and for performing the reaction effectively. As an example in which (S)-hydroxynitrile lyase was immobilized, the immobilization to a micro cellulose powder and nitrocellulose has been reported. However, these cellulosic carriers have a low absorption ratio of the enzyme, arising inconveniences such that enormous amounts of carriers are necessary to immobilize the enzyme required for the reaction.
The object of the present invention is to provide an immobilized enzyme in which (S)-hydroxynitrile lyase is immobilized in an immobilization carrier at a high absorption ratio, a method for producing said immobilized enzyme, and a method for producing optically active cyanohydrin using said immobilized enzyme.
The inventors of the present invention have studied extensively and intensively to solve above problems and have now found that (S)-hydroxynitrile lyase could be immobilized at high absorption ratio by use of a porous inorganic carrier such as a sintered clay carrier, a silica carrier, an alumina carrier, and a silica alumina carrier as an immobilization carrier for enzyme, thereby completing the present invention.
The present invention relates to an immobilized enzyme in which (S)-hydroxynitrile lyase is immobilized in a carrier comprising a porous inorganic material (e.g. the sintered clay carrier, the silica carrier, the alumina carrier, or the silica alumina carrier, having a pore size of 10-80 nm). (S)-hydroxynitrile lyase used herein can be derived from a plant of Euphorbiaceae, Poaceae(Gramineae) or Olacaceae.
The present invention also relates to a method for producing the immobilized enzyme in which (S)-hydroxynitrile lyase is immobilized in a carrier comprising a porous inorganic material (e.g. the sintered clay carrier, the silica carrier, the alumina carrier or the silica alumina carrier, having the pore size of 10-80 nm). (S)-hydroxynitrile lyase used herein can be derived from a plant of Euphorbiaceae, Poaceae(Gramineae) or Olacaceae.
The present invention further relates to a method for producing an optically active cyanohydrin, comprising bringing said immobilized enzyme into contact with a carbonyl compound and a cyanogen compound in the presence of a slightly water-soluble or water-insoluble organic solvent. The immobilized enzyme used herein may be collected to be reused from the reaction mixture.
The present invention will be described in detail as follows.